Method and apparatus for oscillating a continuous casting mold

ABSTRACT

A continuous casting mold, having either a straight or a curved casting cavity, is pivotally mounted to a frame that reciprocates vertically and pivots upon a horizontal axis through the mold as it reciprocates. A cast strand emerging from the mold curves toward the horizontal under the combined influence of the pivotal and reciprocal motion of the mold.

tilted tats Patet Newhall et al. Feb, ll, N72

[54] 3,409,070 11/1968 CiOChCItO ..164/261 OSCILLATHNG A CONTINUOUS 3,395,751 8/1968 Hess ..164/260 CASTING MOLD [72] Inventors: Henry S. Newhall, Allison Park; Rufius Easton, Pittsburgh, both of Pa.

[73] Assignee: Koppel-s Company, Inc.

[22] Filed: Jan. 5, 1970 [21 Appl. No.: 639

[52] US. Cl ..164/83, 164/260, 164/281 [51] .WBZZd 1 1/02, B22d 27/08 [58] ..164/83,260, 261,281,282

[56] References Cited 7 t ,7 is 7 7 A @IITED sg gsylsw- 35 86 2 911910 Ea t?" Primary Examiner-J. Spencer Overholser Assistant Examiner-John E. Roethel Att0rneySherman H. Barber, Oscar B. Brumback and Glin E. Williams [57] ABSTRACT A continuous casting mold, having either a straight or a curved casting cavity, is pivotally mounted to a frame that reciprocates vertically and pivots upon a horizontal axis through the mold as it reciprocates. A cast strand emerging from the mold curves toward the horizontal under the combined influence of the pivotal and reciprocal motion of the mold.

13 Claims, 5 Drawing Figures PATENTED FEB 1 I972- SHEET 2 OF 2 INVENTORS HENRY s. NEW/{ALL & RUFUS EASTON BY Q5340 rf larnag METHOD AND APPARATUS FOR OSCILLATING A CONTINUOUS CASTING MOLD BACKGROUND OF THE INVENTION The present invention relates to continuous metal casting and, more particularly, to method and apparatus for oscillating the mold of the continuous casting machine.

With the introduction of the curved continuous casting mold, it became necessary to provide a practical means for oscillating the mold in a vertical plane and the same time moving the mold on an are having a center at considerable distance from the mold. Some of the mold operating mechanisms found in the prior art are massive pieces of machinery, and practically all of them utilize a long radial arm connected to a center point and to the mold with a mechanism for pivoting the radial arm about the center so that the mold itself moves along an are. Some cured mold oscillating devices include rollers and tracks with which the mold cooperates, but which are very difficult to keep in condition and to maintain so that the mold does not deviate unnecessarily from a true circular arc.

That such curved mold oscillating devices that are available in the prior art are bulky, costly, and difficult to keep in proper condition of maintenance is readily apparent to those skilled in the art who have used some of these devices.

How the equipment of the present invention overcomes the deficiencies of the prior art devices and methods will be readily apparent from the following description of an embodiment of apparatus in accordance with the invention for carrying into practice the method of the invention.

SUMMARY OF THE INVENTION The method and apparatus for oscillating a continuous casting mold comprises reciprocating the mold in a vertical plane and pivoting the mold about a horizontal axis through the mold as it reciprocates with means coacting with the mold to limit the pivotal movement of the mold as it reciprocates vertically.

For a further understanding of the invention and for advantages and features thereof, reference may be made to the following description in conjunction with the drawings which show, for the purpose of exemplification, one embodiment of the invention suitable for carrying into practice the method of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a schematic elevational view of a portion of a continuous casting machine in accordance with one embodiment of the invention;

FIG. 2 is a schematic elevational view of a modification of the apparatus of FIG. 1;

FIG. 3 is a detail of the mold of FIG. 1;

FIG. 4 is a modification of the mold of FIG. 3; and

FIG. 5 is a modification ofthe mold of FIG. 3.

DETAILED DESCRIPTION Referring to FIG. 1, a continuous casting mold oscillating system 11 in accordance with the invention includes a vertically oriented casting mold 13 having a straight internal casting cavity 15, and the mold is provided with trunnions 17 that are journaled in diametrically opposite bearings 19. The bearings 19 are supported on a frame 21 surrounding the mold 13. To the frame 21 there are attached a pair of vertically downwardly extending straight guide members 23.

The straight vertically extending guide members 23 coact with upper 25 and lower 27 pairs of guide rollers that are mounted to a fixed structure 29 comprised of horizontal and vertical structural members. The lower end of the members 23 are connected to a mold reciprocating mechanism 31 through a pivotally connected link 33. The mold reciprocating mechanism 31 comprises an arm 35 pivoted at 37 to the supporting structure 29, and a fluid-actuated cylinder-piston assembly 39.

The frame 21 has depending clevises 41 which are pin connected to the eye end of piston rods 43 forming a part of cylinder-piston assemblies 45 that are pivotally connected to the structure 29. Such cylinder-piston assembly 45 contains a compression spring (not shown) acting on and urging the piston rod 43 upward.

The support structure 29 also carries pairs of fixed other upper 47 and lower 49 rollers that coact with and guide the downwardly extending members 23 when they move vertically in the manner described hereinafter.

FIG. 2 illustrates another continuous casting mold oscillating system 51 in accordance with the modification of the invention, that includes a vertically oriented casting mold 53 having an arcuate internal casting cavity 55. The mold 53 is provided with trunnions 57 that are journaled in bearings 59 fixed to a frame 61 that surrounds the mold 5.3.

To the frame 61 there are attached a pair of vertically downwardly extending arcuate guide members 63 that coact along their arcuate edges with upper 65 and lower 67 pairs of guide rollers that are mounted to a fixed supporting structure 69. The lower pair of guide rollers 67, as may be noticed from FIG. 2, are offset laterally from the upper pair of guide rollers 65.

The fixed supporting structure 69 also carries upper 71 and lower 73 pairs of other guide rollers that coact with the flat surfaces of the arcuate guide members 63.

The lower ends of the arcuate guide members 63 are pivotally connected through a link 75 with a mold reciprocating mechanism that includes an arm 77 journaled at 79 to the supporting structure 69. The arm 77 is pivotable about the journal 79 by a crank 81 eccentrically mounted to a suitable rotary mechanism 03.

The frame 61 is provided with depending clevises 85 that are pin connected to the eye end of piston rods 87 forming a part of cylinder-piston assemblies 89. The cylinder-piston assemblies 89 are provided with internal springs like those mentioned before and they are pin connected, as at 91, to the fixed supporting structure 69, about where shown in FIG. 2.

FIG. 3 illustrates a detailed portion of a continuous casting apparatus which is like that of FIG. 1, but which is modified to the extent that a casting mold 93 has an arcuate internal casting cavity 95 instead of a straight casting cavity as in mold 13. The mold 93 is also provided with trunnions 97 that are journaled in bearings 99 mounted to a frame 101 surrounding the mold 93.

The frame 101 has depending clevises 103 that cooperate with the eye ends of piston rods 105 that are similar to and operate like the piston rods 43.

The frame 101 also carries an adjustable mold pivotrestraining mechanism 107 comprised of a pair of diametrically opposed depending lugs 109 which have threaded holes therethrough with which a bolt 111 cooperates, and a lock nut 1 l3 threaded on each bolt 111.

The outer surface of the mold 93 is provided with a pair of diametrically opposed pads 115 located on the axis of the bolts 111. The pads 115 are adapted to coact with the bolts 111 in the manner described hereinafter.

The mold 93, like the molds 11 and 53, is provided with conventional cooling water inlet 117 and cooling water outlet 119 connections; cooling water flowing into the mold 93 in the direction of the arrow A and flowing from the mold 93 in the direction of the arrow B.

It will be noted from FIG. 3 that the inner arcuate mold surface of the mold cavity 95 is tangent to a vertical plane in along a line of tangency that is parallel to and lies in a horizontal plane 123 containing the horizontal axis of the trunnions 97.

FIG. 4 illustrates a detail of a continuous casting mold 125 that is similar to the mold 53 of FIG. 2.. In this instance, the mold 125 has an arcuate internal casting cavity 127, and the inner surface of the casting cavity 127 is tangent to a vertical plane 129 at the bottom of the mold 125. The mold 125 is provided with a diametrically opposite pair of trunnions 131 that are journaled in bearings 133 fixed to a frame 135 surrounding the mold 125.

The frame 135 carries depending clevises 137 to which are pivotally connected piston rods 139, like the piston rods 87 of FIG. 2. Further, the frame 135 carries a mold pivot-restraining mechanism 141 that is substantially like the mold pivotrestraining mechanism 111, which has been described previously herein.

it should be noted that the piston rods 139 are arranged vertically, but that the piston rods 87, to which the rods 139 are similar are arranged at an angle to the vertical. in other respects, the structure of FIG. 4 is similar to the structure of FIG. 3.

FIG. illustrates a detail of the continuous casting mold 141 having an arcuate internal casting cavity 143; the mold 141 being similar to the mold 93 of FIG. 3. However, in FIG. 5, the mold 141 is provided with a pair of diametrically opposed pins 145 located near the bottom of the mold and that extend outwardly therefrom and coact with arcuate slots 147 in opposite fixed mold guide members 149.

The mold 141 has a pair of oppositely disposed trunnions 151 that are journaled in bearings 153 which are secured to a frame 155 surrounding the mold 141. Likewise, the frame 155 carries a mold pivot-restraining mechanism 157 that is substantially like the pivot-restraining mechanisms 107.

In operation, the mold 13 receives molten metal 159 teeming from the usual tundish (not shown) and the mold 13 and frame 21 are reciprocated vertically by actuating the cylinderpiston assembly 39. The mold l3 and frame 21 move downwardly under the guidance of the rollers 25, 27, 47, 49, and under the influence of the pivoting arm 35, while the compression springs within the cylinder-piston assemblies 45 store energy which is released when the bottom of the down stroke is reached so that the mold and frame move upward to the top position again.

The mold 13, being pivotally mounted on the trunnions 17, is free to swing about the axis of the trunnions 17, but within the limit set by the pivot-restraining mechanism 107. Wherefore, a cast strand 161 emerging from the mold cavity 15, readily curves toward the horizontal since the mold is free to pivot about the trunnion axis and assume a tangent position toward the curved strand 161. The strand 161 is already curved by virtue of being withdrawn initially in an arcuate form from the mold using a curved starting bar like that described in US. Pat. No. 3,344,844 or that described in application Ser. No. 868,353 filed Oct. 22, 1969.

So, too, the mold 93 of FIG. 3 receives molten metal 159, and bath mold 93 and frame 101 are reciprocated vertically by actuating a mechanism similar to the apparatus 31 of FIG. 1. The mold 93 and move frame 101 move vertically under the restraint imposed by the upper and lower pairs of rollers 25, 27, 47, 49 acting on the dependent members 23, but the mold 93 is also pivotal about the axis of the trunnions 97. Wherefore, a cast strand 163 emerging from the mold Q3 readily curves toward the horizontal since the pivoting mold 93 offers a minimum of resistance.

The mold 125 of FIG. 4 is a variant of the mold 93 of FIG. 3, wherein the pivot-restraining mechanism 107 has been so set that the tangent plane 129 is tangent to the inner arcuate surface of the mold cavity along a line at the bottom of the mold 93 and a minimum of resistance is offered to the strand 165 emerging from the mold 125.

The mold 141 and frame 155 of F IG. 5 are reciprocated by a mechanism similar to the mechanism 31"of FIG. 1, and the mold 141 pivots about the axis of the trunnions 151 due to the guiding influence of the arcuate slots 147 on the pins 145. As cast strand 167 emerges from the mold 141, it readily curves toward the horizontal under the influence of the pivotable mold as directed by the pins 145 in the arcuate slots 147.

A significant feature and important advantage is found in the mold arrangement of FIG. 4 which is that any nonmetallic inclusions that may be present in the molten metal core tend to float vertically upward toward the free surface of the molten metal in the mold, nd such nonmetallic inclusions are most apt to reach the free surface of the molten metal than nonmetallic inclusions in the molten metal cores of strands cast in the molds of FIGS. 1-3 and 5.

That this is so will be readily apparent to those skilled in the art when they recognize from P10. 4 that nonmetallic inclusions that are deep down within the molten metal core of the strand float unobstructedly upward without being stopped by contact with the thin skin of the strand. Whereas, nonmetallic inclusions in the metal core of strands cast in the molds of FIGS. l-3 and 5 do not float unobstructedly upward from as deep a location in the strand. The nonmetallic inclusions in strands cast in the molds of FIGS. 13 and 5 soon contact the solid skin of the strand and are held captive there only to become surface defects in billets that are cut from the strand and rolled later on.

Those skilled in the art will recognize from the foregoing description several significant features and advantages, among which are:

That for various product uses to which cast strands will be assigned and for various quality levels of steel produced, the machine operator may quickly and easily adjust the position of the mold of the present invention to locate the line of tangency at the optimum position;

That the amount of mold pivoting may be varied to suit other casting conditions by merely adjusting the position of the bolts in the pivot-restraining mechanisms;

That the mold oscillating system in accordance with the invention reciprocates the mold vertically, but that the mold is free to pivot about a horizontal axis through the mold whereby the strand emerging from the mold curves toward the horizontal; and

That the mold oscillating system of the invention is simpler and less costly than oscillating systems known from the prior art.

Although the invention is described herein with a certain degree of particularity, it is understood that the disclosure has been made as an example and that the scope of the invention is defined by what is hereinafter claimed.

We claim:

1. In a continuous casting machine the improvement comprising:

a. a vertically oriented flow-through casting mold from which a cast strand emerges and curves toward a horizontal attitude;

b. a frame to which said mold is pivotally mounted and movable about a horizontal axis;

c. an adjustable mechanism fixed to said frame and coacting with said mold for limiting the pivotal movement of said mold; and

d. means for reciprocating said frame and mold which pivots about said axis and assumes a tangential attitude to said curved strand.

2. The invention of claim 1 wherein:

a. said mold has a straight casting cavity wherein molten metal partially solidifies and forms said cast strand.

3. The invention of claim 1 wherein:

a. said mold has an arcuate casting cavity wherein molten metal partially solidifies and forms said cast strand.

4. The invention of claim 1 including:

a. guide means coacting with said frame for maintaining the reciprocating movement of the frame along a vertical axis.

5. The invention of claim 3 including:

a. guide means for directing the motion of the frame along a preselected arcuate path in a vertical plane.

6. In a continuous metal casting machine the improvement comprising:

a. a vertically oriented flow-through casting mold having ar cuate surfaces forming part of a casting cavity from which a cast strand is continuously withdrawn;

comprising:

. a vertically oriented flow-through casting mold from which a cast strand is continually withdrawn; a frame to which said mold is mounted for pivotal movement abut a horizontal axis through said mold; means for reciprocating said frame vertically; means guiding one end of said mold along an arcuate path as said frame reciprocates and said mold pivots, whereby said cast strand is curved toward a horizontal attitude; and

an adjustable mechanism for limiting the amount of pivotal movement ofsaid mold. ln a continuous metal casting machine the improvement comprising:

. roller means mounted to said fixed support and coactive with said guide member for guiding said frame in a vertical plane;

means connected to said guide member for reciprocating said frame and said mold vertically;

resiliently biased means connecting said frame and said fixed supporting structure for urging said frame and mold upwardly; and

means mounted to said frame and coactive with said mold in limiting the pivotal movement of said mold about said horizontal axis. 10. In a continuous metal casting machine the improvement comprising:

a. a vertical casting mold having arcuate surfaces forming parts of an internal casting cavity;

b. a frame surrounding said mold;

c. means supporting said mold to said frame for pivotal movement about a horizontal axis through said mold;

d. an arcuate guide member connected to said frame;

e. a fixed support located adjacent said frame;

f. roller means mounted to said fixed support and coactive with said guide member for guiding said frame in a vertical plane;

g. means connected to said guide member for reciprocating said frame and said mold vertically;

h. resiliently biased means connecting said frame and said fixed supporting structure for urging said frame and mold upwardly; and

means mounted to said frame and coactive with said mold for limiting the pivotal movement of said mold about said horizontal axis, one position of said mold being such that a vertical plane is tangent to the inner arcuate surface at a line lying in a horizontal plane of said horizontal axis.

11. The method for oscillating a continuous metal casting mold from which a cast strand is continuously withdrawn comprising the steps:

a. reciprocating the mold in a vertical plane;

b. pivoting the mold about a horizontal axis through the mold as said mold reciprocates; and

c. providing adjustable means for restricting the amount said mold pivots as said mold reciprocates.

12. The method of claim 11 wherein:

a. said mold reciprocates along an arcuate path in a vertical plane.

13. the method ofclaim 11 wherein:

a. said mold reciprocates vertically along a straight line in a vertical plane. 

1. In a continuous casting machine the improvement comprising: a. a vertically oriented flow-through casting mold from which a cast strand emerges and curves toward a horizontal attitude; b. a frame to which said mold is pivotally mounted and movable about a horizontal axis; c. an adjustable mechanism fixed to said frame and coacting with said mold for limiting the pivotal movement of said mold; and d. means for reciprocating said frame and mold which pivots about said axis and assumes a tangential attitude to said curved strand.
 2. The invention of claim 1 wherein: a. said mold has a straight casting cavity wherein molten metal partially solidifies and forms said cast strand.
 3. The invention of claim 1 wherein: a. said mold has an arcuate casting cavity wherein molten metal partially solidifies and forms said cast strand.
 4. The invention of claim 1 including: a. guide means coacting with said frame for maintaining the reciprocating movement of the frame along a vertical axis.
 5. The invention of claIm 3 including: a. guide means for directing the motion of the frame along a preselected arcuate path in a vertical plane.
 6. In a continuous metal casting machine the improvement comprising: a. a vertically oriented flow-through casting mold having arcuate surfaces forming part of a casting cavity from which a cast strand is continuously withdrawn; b. a frame to which said mold is mounted for pivotal movement about a horizontal axis through said mold; and c. means orienting said casting cavity so that a plane tangent to an arcuate surface of said casting cavity at the bottom of said mold is vertical.
 7. The invention of claim 6 including: a. an adjustable mechanism for limiting the pivotal movement of said mold about said axis.
 8. In a continuous metal casting machine the improvement comprising: a. a vertically oriented flow-through casting mold from which a cast strand is continually withdrawn; b. a frame to which said mold is mounted for pivotal movement abut a horizontal axis through said mold; c. means for reciprocating said frame vertically; d. means guiding one end of said mold along an arcuate path as said frame reciprocates and said mold pivots, whereby said cast strand is curved toward a horizontal attitude; and e. an adjustable mechanism for limiting the amount of pivotal movement of said mold.
 9. In a continuous metal casting machine the improvement comprising: a. a vertical casting mold having a straight internal casting cavity; b. a frame surrounding said mold; c. means supporting said mold to said frame for pivotal movement about a horizontal axis through said mold; d. a vertical guide member connected to said frame; e. a fixed support located adjacent said frame; f. roller means mounted to said fixed support and coactive with said guide member for guiding said frame in a vertical plane; g. means connected to said guide member for reciprocating said frame and said mold vertically; h. resiliently biased means connecting said frame and said fixed supporting structure for urging said frame and mold upwardly; and means mounted to said frame and coactive with said mold in limiting the pivotal movement of said mold about said horizontal axis.
 10. In a continuous metal casting machine the improvement comprising: a. a vertical casting mold having arcuate surfaces forming parts of an internal casting cavity; b. a frame surrounding said mold; c. means supporting said mold to said frame for pivotal movement about a horizontal axis through said mold; d. an arcuate guide member connected to said frame; e. a fixed support located adjacent said frame; f. roller means mounted to said fixed support and coactive with said guide member for guiding said frame in a vertical plane; g. means connected to said guide member for reciprocating said frame and said mold vertically; h. resiliently biased means connecting said frame and said fixed supporting structure for urging said frame and mold upwardly; and means mounted to said frame and coactive with said mold for limiting the pivotal movement of said mold about said horizontal axis, one position of said mold being such that a vertical plane is tangent to the inner arcuate surface at a line lying in a horizontal plane of said horizontal axis.
 11. The method for oscillating a continuous metal casting mold from which a cast strand is continuously withdrawn comprising the steps: a. reciprocating the mold in a vertical plane; b. pivoting the mold about a horizontal axis through the mold as said mold reciprocates; and c. providing adjustable means for restricting the amount said mold pivots as said mold reciprocates.
 12. The method of claim 11 wherein: a. said mold reciprocates along an arcuate path in a vertical plane.
 13. the method of claim 11 wherein: a. said mold reciprocates vertically along a straight line in a vertical plane. 